Return the completion record result from running a script

The Service Worker spec will use this to detect uncaught runtime errors:
w3c/ServiceWorker#1334.

source

@@ -81974,10 +81974,11 @@ interface <dfn>Location</dfn> { // but see also <a href="#the-location-interface
        <var>script source</var>, <var>settings</var>, <var>base URL</var>, and the <span>default
        classic script fetch options</span>.</p></li>
 
-       <li><p>Let <var>result</var> be the result of <span data-x="run a classic script">running the
-       classic script</span> <var>script</var>. If evaluation was unsuccessful, let
-       <var>result</var> be undefined instead. (The result will also be undefined if <span
-       data-x="concept-bc-noscript">scripting is disabled</span>.)</p></li>
+       <li><p>Let <var>evaluationStatus</var> be the result of <span data-x="run a classic
+       script">running the classic script</span> <var>script</var>.</p></li>
+
+       <li><p>Let <var>result</var> be undefined if <var>evaluationStatus</var> is an <span>abrupt
+       completion</span>, or <var>evaluationStatus</var>.[[Value]] otherwise.</p></li>
 
        <li><p>Let <var>response</var> be null.</p></li>
 
@@ -87371,7 +87372,7 @@ interface <dfn>ApplicationCache</dfn> : <span>EventTarget</span> {
    <li><p>Let <var>settings</var> be the <span>settings object</span> of <var>script</var>.</p></li>
 
    <li><p><span>Check if we can run script</span> with <var>settings</var>. If this returns "do
-   not run" then return.</p></li>
+   not run" then return <span>NormalCompletion</span>(undefined).</p></li>
 
    <li><p><span>Prepare to run script</span> given <var>settings</var>.</p></li>
 
@@ -87426,7 +87427,7 @@ interface <dfn>ApplicationCache</dfn> : <span>EventTarget</span> {
 
        <li><p><span>Clean up after running script</span> with <var>settings</var>.</p></li>
 
-       <li><p>Return undefined.</p></li>
+       <li><p>Return <var>evaluationStatus</var>.</p></li>
       </ol>
      </li>
     </ol>
@@ -87436,15 +87437,17 @@ interface <dfn>ApplicationCache</dfn> : <span>EventTarget</span> {
 
    <li>
     <p>If <var>evaluationStatus</var> is a normal completion, return
-    <var>evaluationStatus</var>.[[Value]].</p>
+    <var>evaluationStatus</var>.</p>
 
     <p class="note">This value is only ever used by the <span data-x="javascript
     protocol"><code>javascript:</code> URL steps</span>.</p>
    </li>
 
    <li><p>If we've reached this point, <var>evaluationStatus</var> was left as null because the
    script was <span data-x="abort a running script">aborted prematurely</span> during evaluation.
-   Return undefined.</p></li>
+   Return Completion { [[Type]]: throw, [[Value]]: a new
+   <span>"<code>QuotaExceededError</code>"</span> <code>DOMException</code>, [[Target]]: empty }.
+   </p></li>
   </ol>
 
   <p>To <dfn data-export="">run a module script</dfn> given a <span>module script</span>
@@ -87456,7 +87459,7 @@ interface <dfn>ApplicationCache</dfn> : <span>EventTarget</span> {
    <li><p>Let <var>settings</var> be the <span>settings object</span> of <var>script</var>.</p></li>
 
    <li><p><span>Check if we can run script</span> with <var>settings</var>. If this returns "do
-   not run" then return.</p></li>
+   not run" then return <span>NormalCompletion</span>(undefined).</p></li>
 
    <li><p><span>Prepare to run script</span> given <var>settings</var>.</p></li>
 
@@ -87485,7 +87488,7 @@ interface <dfn>ApplicationCache</dfn> : <span>EventTarget</span> {
       <var>evaluationStatus</var> to Completion { [[Type]]: throw, [[Value]]: a new
       <span>"<code>QuotaExceededError</code>"</span> <code>DOMException</code>, [[Target]]: empty
       }.</p>
-     </li>
+      </li>
     </ol>
    </li>
 
@@ -87502,6 +87505,8 @@ interface <dfn>ApplicationCache</dfn> : <span>EventTarget</span> {
    </li>
 
    <li><p><span>Clean up after running script</span> with <var>settings</var>.</p></li>
+
+   <li><p>Return <var>evaluationStatus</var>.</p></li>
   </ol>
 
   <p>The steps to <dfn>check if we can run script</dfn> with an <span>environment settings